Evil Mad Scientist Laboratories

Making the world a better place, one Evil Mad Scientist at a time.

LED Micro-Readerboard, version 2.0

We’ve just finished updating the LED Micro-Readerboard (formerly the micro-readerboard LED ornament) to version 2.0. This version features longer battery life, the use of a standard common-cathode LED display, and a new set of phrases including optional holiday phrases. It’s an open-source project so you can download the code, order some parts, and go to town.We are also making it available as a kit, exclusively through the Make Store. The kit features a remarkable high-intensity LED display that enables vastly improved battery life.

Our LED Micro-Readerboard is a fun little open source project that provides an introduction to the capabilities of microcontrollers. Once assembled, the readerboard spells out simple preprogrammed messages such as “MAKE,” or “HELLO WORLD,” one letter at a time on its bright single-character alphanumeric LED display. Each time that its power switch is turned off and back on, it
picks a new message from its memory to repeat.
With the default firmware, fifteen phrases are included and a bank of optional holiday messages can be enabled as well– in case you want to use it as a holiday ornament. The kits come with pre-programmed microcontrollers, so no programming is actually needed– making it a simple electronics soldering project.

Assembly is easy with comic book style instructions.
Printed instructions are included with kits, but you can also download the instructions here. (388 kB PDF File).

The kit includes a pre-programmed Atmel ATtiny2313 microcontroller, a superbright alphanumeric LED display, a battery box with switch, as well as the printed instructions.

Two AA batteries are required, as well as standard soldering equipment. A hot glue gun is nice as well.
( If you are in doubt about whether this project is for you, you just might want to skim through the kit instructions before you started. )

The LED display used in the kit is a (seriously awesome) ultra-high brightness, deep red 16-segment alphanumeric display.
The display is run in a low-duty cycle mode, where each LED segment is only on for a very small fraction of the time.

Even so, because the display is so efficient, the display is still readably bright while drawing little enough average current that the typical battery life is in excess of three weeks.

If you do want to reprogram the LED Micro-Readerboard, you have several options. We have released the source code under the GPL for those that would like to hack it.
You can take the kit and reprogram it with your own set of phrases, or change the firmware to give it completely different behavior. You can also just build your own from scratch without buying a kit; download the firmware, gather your parts, and get busy. However, note that if you are going to reprogram the chip, do so before assembly, or build it with the addition of a socket– it cannot be reprogrammed while attached to the LED display.
Download Source code (16 kB .ZIP file), for AVR-GCC, licensed under the GPL.
We have some reference data up for this project already. So far, we have a short but growing list of FAQs, a set of technical data to help you build your own and a place for support discussions.
So, have fun building, and please post pictures of your projects in the Evil Mad Science Auxiliary!